1. Technical Field of the Invention
The present invention relates generally to semiconductor packaging and, more particularly, to a semiconductor package provided with a thermal tape window frame which is adhered to the mold compound or package body of the semiconductor package and is adapted to provide both a low cost heat sink attachment and high dielectric constant (K) thermal solution.
2. Description of the Related Art
As is well known in the electronics field, semiconductor devices are often manufactured in package form, in which encapsulant materials or mold compounds provide environmental protection to the integrated circuit(s) or semiconductor die(s) of the semiconductor package. The mold compound, which ultimately hardens to form the package body of the semiconductor package, is exposed to heat generated by the semiconductor die(s) of the semiconductor package during the operation thereof. However, the encapsulant materials or mold compounds used to form the package body are typically plastics which are poor thermal dissipaters. In this regard, overheating of the semiconductor package can damage the semiconductor die(s) or other internal devices thereof, thus disrupting the operation of the semiconductor package and potentially causing dangerous electrical shorts. In order to minimize the risk of overheating, some semiconductor packages known in the art are provided with a heat sink or heat transfer system that conducts heat away from the internal semiconductor die(s) to the ambient environment.
One currently known semiconductor package widely used in various applications is referred to as a Flip Chip BGA or FCBGA package. Known sub-categories for FCBGA packages include Bare Die FCBGA packages, and Single Piece Lid (or SPL) FCBGA packages. In those FCBGA packages which are used in conjunction with a heat sink, the attachment of the heat sink thereto is typically facilitated through the use of one of two primary attachment methods. For high power applications, expensive mechanical attachment methods are used in conjunction with high K thermal interface materials (or TIM's). The mechanical attachment methods utilize machined or stamped fixtures that have springs, screws, clamps, latches or other physical devices to secure the heat sink to the FCBGA package. For low power applications, thermal tapes are used for the mechanical attachment of the heat sink to the FCBGA package, though the resultant thermal dissipation is limited.
More particularly, for Single Piece Lid or SPL FCBGA packages, the semiconductor die of such package has a TIM material between itself and the lid. This TIM material typically has a thin bond line and often comprises high K materials such as a grease or gel. For the heat sink attachment to the SPL FCBGA package, one of two primary methods is typically used, as indicated above. In a first one of such heat sink attachment methods, a strip of adhesive thermal tape having a lower K value is used, with such tape mechanically securing the heat sink to the SPL FCBGA package. Alternatively, for high power applications, a higher K TIM material is typically used to define the interface between the heat sink and the SPL FCBGA package, though the use of such higher K material requires the implementation of an additional step of securing the heat sink to the package. As also indicated above, such additional heat sink securing step typically entails some mechanical method such as the use of springs, screws, clamps, latches, etc. For Bare Die FCBGA packages, low K or high K TIM materials are used to facilitate the interface between the heat sink and such packages based on power dissipation requirements, though there still remains the need for a mechanical attachment method to secure the heat sink to the Bare Die FCBGA package.
Thus, as is apparent from the foregoing, there exists a need in the prior art for a packaging solution wherein a higher K TIM material may be used to facilitate the interface between a heat sink and a semiconductor package without requiring the further need for the implementation of a mechanical attachment method as described above. The present invention addresses this need by providing a semiconductor packaging solution wherein a high K thermal material such as a grease or gel is placed in a controlled thin bond line between the semiconductor die of the package and the heat sink in a direct manner using a thermal tape window frame as the low cost mechanical attachment mechanism. As the main thermal dissipation path is between the backside of the semiconductor die and the heat sink, a high K TIM material can be used to maximize thermal dissipation in a manner that does not require expensive mechanical attachment methods. These, as well as other features and advantages of the present invention, will be discussed in more detail below.